Barnacles may look nice and nautical on things like rocks, but they’re a major problem for watercraft of all sorts. On the hulls of ships, for example, they can drastically decrease the vessel’s hydrodynamics, causing it to burn more fuel and emit more emissions in order to maintain its cruising speed. The most common way of keeping barnacles off those hulls involves the use of environmentally-unfriendly paints. Now, however, a scientist from Sweden’s University of Gothenburg has developed what could be a less harmful alternative.